In the depths of the Depression, architect Frank Lloyd Wright developed a housing style called Usonian. These middle-class homes were meant to be affordable and connected to their setting. They blurred the distinction between indoors and out, featuring plenty of glass, extended roofs and a carport (a word Wright coined). The Rosenbaum House in Florence, Ala., has been called the purest example of the Usonian style.

Why it's a treasure: When newlyweds Mildred and Stanley Rosenbaum moved into their home in 1939, crowds gathered to gawk at the unusual flat-roofed building. Over decades, the house deteriorated and was destined for demolition until the city bought it and its citizens restored it through a 1% sales tax.

Why you'd want to live here: Floor-to-ceiling glass keeps things bright, an open kitchen puts the cook in the middle of family life, and built-in bookshelves and nooks create cozy spaces. It's not hard to imagine making this home. As for Florence, it's a hip college town, home to fashion designers and the W.C. Handy Blues Festival, and across the Tennessee River from Muscle Shoals' famed recording studios.

Why you wouldn't: With a leaky roof and faulty in-floor heating, the owners lived with buckets and space heaters. Air-conditioning? Wright never liked it, even for a client in Alabama. And a retrofit never worked well. Even with problems resolved during restoration, the house could use more storage space, and the architect's furniture emphasizes looks over comfort.

The surprise: Wright's 1948 addition put the four Rosenbaum boys in a dormitory with bunk beds. It feels like the Brady Bunch, Dixie style.